Many spinal fixation systems have been developed for use in correcting and stabilizing spinal defects and facilitating spinal fusion. Typically, one or more rods are placed adjacent the spinal column in a longitudinal direction and are fixed to the vertebrae. Such systems are described in U.S. Pat. Nos. 5,688,275 and 6,080,156.
In certain situations it is desired to provide transverse stability and rigidity to the implanted spinal rods. Such systems are described in U.S. Pat. Nos. 5,527,314, 5,716,355, and 6,551,318. Existing transverse connecting devices are generally of two types: adjustable connectors and fixed connectors. Adjustable devices have the advantage of being able to accommodate different distances between the spinal implant rods. They also allow the compression or distraction between the two spinal implant rods. However, they usually have the disadvantage of being complicated and involving several components that must be assembled during surgery. Fixed transverse connectors are generally simple and easy to use. They may be composed only of one piece with two setscrews. They may have a relatively low profile, can be loaded on top of the spinal implant rods, and can also be bent to conform to the anatomy. However, they lack the ability to adjust to different distances between the spinal implant rods. Fixed transverse connectors come in incremental lengths, which makes the inventory large. Use of both types of systems often requires attachment of the transverse connector components to the spinal implant rods prior to implanting the longitudinal spinal implant rods. This requires significant pre-operative planning and does not allow modification of the system, such as adding connectors, during the procedure.